Vehicle-tire.



Patented Aug. l2, |902. F. 5.086000 & F. F. BRADLEY.

VEHICLE TIRE.

(Application filed Feb. 17, 1902.)

(No Model.) l

UNITED STATES PATENT OFFICE.

FRED E. OSGOOD AND FRANKLIN F. BRADLEY, OF CHICAGO, ILLINOIS, AS- SIGNORS OF ONE-THIRD TO RICHARD A. KENT, OF CHICAGO, ILLINOIS.

VEHICLE-TIRE.

SPECIFICATION forming part of Letters Patent No. 706,590, dated August 12, 1902. Application iiled February 17, 1902. Serial No.94=,549. (No model.)

To all whom it may concern.: in which a core of sponge-rubber has been Be it known that we, FRED E. OSGOOD and surrounded by a rubber tube. It has also FRANKLIN F. BRADLEY,citiz"ens of the United been proposed to manufacture such a tire by States, residing at Chicago, county of Cook, surrounding a core formed of sponge-rubber 5 State of Illinois, have invented a certain new and ammonium carbonate by a rubber covand useful Improvement Vin Vehicle-Tires; ering and then heating the tire, thereby deand we declare the following to be a full, composing theammonium carbonate and vulclear, and exact description of the invention, canizing the rubber covering. As the core besuch as will enable others skilled in the art to fore heating completely fills thespace within 6o lo which it pertains to make and use the Same, the outer covering, the resulting tire is solid reference being had to the accompanying and does not possess the requisite resiliency. drawings, which form a part of this specifica- Our invention will be more fully ldescribed tion. hereinafter with reference to the accompany- Oar invention relates in general to tires for ing drawings, in which the same is illustrated I5 wheels, and more particularly torubber tires as embodied in two convenient and practical for bicycles, automobiles, or other vehicles. forms, and in whichl In order that the tires of vehicles may pos- Figure l is an elevational view of a tire emsess sufficient resiliency to reduce the jar or bodying our invention, part thereof being shock resulting from uneven roads, it is comshown in section; Fig. 2, an enlarged cross- 7o zo mon to manufacture tires of `solid rubber or sectional View showing the tire before vulof rubber with an air-space between the rims canizing; Fig. 3, a view similar to Fig. 2, of the wheelsand the tires known as cushshowing the tire after vulcanizing; and'Figs. ion-tires, or of rubber tubes adapted to conl and 5, views similar to Figs. 2 and A3, showtain compressed air, knownl as pneumatic ing a modified embodiment of our invention. 25 tires. The solid and cushion tires are ob- Similar reference characters are used to desjectionable, as they are necessarily quite ignate similar parts in the several views of heavy and also because ofptheir limited rethe drawings. siliency. The objectionsto pneumatic tires Referring particularly to Figs. l, 2, and 3, are their liability to be punctnred and their reference-letter A indicates the outer cover- 8o 3o lack of durability. ing of the tire, whichis' composed of some The object of our invention is to produce durable material, preferably rubber, the a resilient tire which will be light in weight, thickness of which along the portion thereof thereby avoiding the objection to solid tires, which serves as a tread of the tire is thicker, which willcontinue in its normally-distended as shown at ct, so as to prolong the life of the 35' condition and not become permanently flattire by reinforcing the portion thereof where tened by use, as Willa cushion-tire, and which the greatest wear occurs. In close contact will not be injured by punctures, thereby obwith the inner surface of the outer covering viating the' disadvantage incident to pneu- A is a protecting and strengthening layer B, matic tires. y formed of any suitable material-such, for 9o 4o Our invention, brieiiy described, comprises instance, as canvas-which serves as a casa process for manufacturing resilient tires, ing for the inner` part of the tire and to preconsisting in forming a'rubber tube of the vent the prenetration of sharp objects through size desired for the tire, inclosing within the the same into the interior of `the tire. `The tube a core of less bulk than the space within space within the protecting-layer Bis filled 45 the tube and composed of a mixture of an by a resilient and porous materialsuch, for expansible material and a gas producing instance, as sponge-rubber-the interstices chemical, and subjecting the tire to sufficient of which are filled withgas under tension, heat to vulcanize the rubber tubeand decomthereby imparting to the tire the desired repose the chemical,thereby expanding the core siliency,.at the same time maintaining the Ico 5o to fill the space within the tube. same normally distended. As the porous Ina- Prior to our invention tires have been made terial comprises innumerable separate cells or interstices containing the gas under pressu re, the penetration of the tire at any one point liberates the gas from the pores Whichare penetrated only and does ,not permit the escape of the gas from theinterior of the rest of the tire. Consequently a puncture does not injuriously atect thel Whole tire, but only the small portion thereof directly punctured. Should the tire be cut so as to cause the outer covering to open to an extent which would endanger the durability of the tire,such cut may be closed by cement or in any suitable manner. The p1 eferred method of constructing the tire, as illustrated in Figs. 1 and 3, is

'to locate within the protecting layer B a massv of material C insufficient to completely iill the space Within the tire, after which the protecting-covering B and the outer covering A are closed in a manner common in the art of making pneumatic tires. rlhe core C consists ina material capable of being expanded and then retained permanently in such expanded condition-as, for instance, uncured spongerbber stock. The uncured sponge-rubber stock or other equivalent material prior to being closed Within the tire is mixed With a chemical capable of being decomposed, so as to form a gas when subjected to heat. While We do not Wish to limit ourselves t'o any particular chemical, We have found in practice that a metallic salt-such, for instance, as ammonium carbonate-is capable of giving good results. After the core C has been inclosed within the outer covering the tire is subjected to the degree of heat necessary for vulcanization of the rubber, which decomposes the chemical, thereby liberating a gas which expands throughout the interstices of the core and is confined in the innumerable separate cells throughout the expanded core. During the process of vulcanization the outer covering surrounding the core does not expand. Consequently the initial exterior diameter of the tire remains the same When it is finished. Prior to inserting the core C Within theouter covering of the `tire it is preferably so formed as to have a circular crosssection the diameter of which is enough smaller than the interior diameter of the completed tire to permit the core to expand when the gas is liberated-from the chemical during k.fied embodiment of our invention, in which,

as in the form shown in Figs. Yl, 2, and 3, an outer covering A', having a reinforced tread a', is provided, within which is located a protecting layer B'. The core is, however, formed tubular, With an air-space D in the center thereofv In this embodiment of our invention the core C is formed of an exterior diameter corresponding to thc interior diameter of the protecting material B', which, together with the outer covering A', is Wrapped around the core C and secured in 'any Well-known manner. Prior to locating the core CWithin the outer covering it is run through a tubingmachine having a mandrel of sufficient size to form the interior air-space D. The material ot' Which the core C' is formed may be the same as that of the core Cin the embodiment of our invention shown in Figs. l, 2, and 3- namely, a mixture of ordinary rubber stock so made as to be capable of vulcanization and a chemical--such as ammonium carbonate, for instance-which is capable of being decomposed, and thereby forming a gas upon the application thereto of the same degree of heat required for vulcanizing the rubber. The tire isvshown in Fig. 4 as it appears .prior to vulcanizing, While in Fig. 5 the tire is illus trated in its complete form, the same having been subjected to the necessary heat to vulcanize the rubber, Which has also decomposed the chemical, and thereby liberated the gas, which has permeated throughout the pores of the core and imparted the requisite tension to the tire.

While the finished tire may, as illustrated in Fig. 5, have a small openingin the center thereof, it ispreferable that the bulk and proportion of ingredients in the mixture should be such as to completely ll the space Within the outer covering, as shown in Fig. 3, when subjected to the requisite heat.,

The tension of the completed tire may be regulated by Vr'the amount ot the chemical mixed with the rubber stock, as the volume of liberated gas is of course dependent upon the amount of the chemical used. The Weight and resiliency of the tire may be regulated by the amount of stock used in the core, so that when it expands the proportion of increase in its bulk WillY be greater or less, as desired.

From the foregoing description it will be observed that We have invented an improved process for manufacturing a vehicle tire which possesses the resiliency of a pneumatic tire without the liability to be injured by punctures, and although of a Weight only slightly greater than a pneumatic tire possesses the durability of a solid tire.

While We have described more or less precisely the details of construction, We do not Wish to be understood as limiting ourselves thereto, as We contemplate changesin form, the proportion of parts, and the substitution of equivalents as circumstances may suggest or render expedient Without departing from the spirit of our invention.

Having now fully described our invention, what We claim as new, and desire to secure by Letters Patent, isi-'- 1. The process of manufacturing vehicle` tires which consists in inclosing Within an IOO IIO

outer covering a core of less bulk than the space Within the covering and composed of a mixture of an expansible material and a chemical capable of generating gas when heated, and heating said mixture to generate a gas and permanently expand the core to completely lill the space within the outer covering without expanding said covering the initial exterior diameter of Which remains the same in the nished tire.

2. The process of manufacturing Vehicletires which consists in inclosing Within an outer covering a core of less bulk than the space Within the covering composed of a mixture of rubber stock and ammonium carbonate, and subjecting the tire to heat whereby the ammonium carbonate is decomposed and the core expanded to lill the space Within the outer covering without expanding said covering the initial exterior diameter of which remains the same in the finished tire.

3. The process of manufacturing Vehicletires which consists in forming a tube of the size desired for the tire, inclosing Within the tube a core of less bulk than the space within the tube composed of a mixture of expansible material and a gas-producing chemical, decomposing the chemical and thereby generating gas and expanding the core to fill the space within the tube Without expanding said tube the initial exterior diameter of which remains the same in the Vfinished tire, and expelling the air from the space Within the tube as the core expands.

4. The process of -manufacturing vehicletires which consists in forming a rubber tube of' a diameter equal to the size of the tire, inclosing in the tube a core of less bulk than the space within the tube composed of' a mixture of rubber stock and ammoniumA carbonate, subjecting the tire to sufficient heat to Vulcanize the rubber tube and decompose the ammonium carbonate thereby generating a gas and expanding the core to fill the space Within the tube Without expanding said tube the initial exterior diameter of which remains the same in the finished tire, and expelling the air from the space within the tube as the core expands.

In testimony whereof We sign this specification in the presence of two Witnesses.

FRED E. OSGOOD. FRANKLIN F. BRADLEY. Vitnesses:

GEO. L. WILKINSON, CLARA C. CUNNINGHAM. 

